High frequency switch



March 31, 1942.

R. F. GUY HIGH FREQUENCY SWITCH Filed Aprih 22, 1939 ATTORNEY.

Patented Mar. 3l, 1942 l 2,278,371 HIGH FREQUENCY SWITCH Raymond F. Guy,Englewood, N. J., assignor to Radio Corporation of America, acorporation oi.'

Delaware Application April 22, 1939, Serial No. 269,406

(Cl. Z50-17) 14 Claims.

This invention relates to a new and useful means of high frequencyswitching and is particularly adapted to the method of switching highpowered radio frequency transmitters which operate on any one of adifferent number of frequencies.

An object of this invention is to provide a system wherein a transmitteris divided into a plurality of units, of which one unit is fixed andother units are movable, the mechanical and electrical circuitarrangement being such that when one of the movable units ismechanically and electrically connected to the fixed unit, the othermovable unit will be simultaneously disconnected from the circuit andphysically moved away from the fixed unit.

Another lobject of this invention is to provide an economical systemwherein the frequency of a transmitter may be quickly changed asrequired from one frequency to another.

A feature of this invention is the arrangement of a fixed unit on aplatform supported by a plurality of guide rails and a plurality ofmovable units riding on the rails and making contact with the fixedunit, the movable units beingso arranged that when one makes contact theother is pushed away and its electrical contacts disconnected. Frequencyswitching means are old in the art, but it has always been a problem to`make a high powered high frequency radio transmitter operate on any oneof a number of frequencies without the necessity of having complicatedmechanical and electrical linkage devices. In the present radiocommunication of international point-topoint or broadcast service, ithas been found necessary to switch frequencies several times during theday. From the standpoint of practical international point-to-pointservice, it is not practical'to have a special high powered transmitterfor each frequency; therefore, it is desirable to have one transmitterso arranged that its frequency can be quickly changed as required. Theswitching system of my invention is a simpliiied method of switchingoperation which consists of a plurality ofmechanical and electricalunits with connection or disconnection means operated by an actuatingmechanism which may be motor-driven or hydraulically operated. Thearrangement of the units is such that a fixed mechanical electric unit,which may be in the form of a power amplifier tube assembly, is mountedin the center of guide rails. Located each side of the tube assembly andmounted on the guide rails by means of rollers or other suitablemechanism, is a movable tank assembly, n

each separate tank assembly being tuned fora different frequency andactuated by suitable mechanism so that the electrical connections lineup perfectly and when one of the movable units is in operation, the unitwill be disconnected.

This invention will best be understood by the accompanying drawing, inwhich:

Fig. l is a plan view of a power amplier of a radio transmitter;

Fig. 2 is a side elevation partly in section, of Fig. l;

Fig. 3 is a schematic plan view showing one fixed unit and three movableunits; and

Fig. 4 is another schematic diagram indicating the use of one fixed unitand four movable units.

Referring now in detail to Figs. 1 and 2 of the drawing, there is showna high powered amplifier employing the features of my invention whichcomprise a xed assembly unit I which may be either a tube assembly or atank assembly, although because of the various interlocks and methods ofwater cooling of tubes, I prefer to maintain the tube assembly as thefixed unit, but it is to be understood that either a tube assembly ortank circuit may be employed. Within the metallic protective casing 2 ofthe xed unit there is shown a plurality of tubes 3 and 4, insulatinglysupported by means of a memberV 5 and having their anodes 6 and 1provided with high voltage contacting elements 8, 8, I0 and II. Otherelectrical connections for switching other parts of the circuit comprisecontacts I2, I3, I4 and I5. Located on the lower portion of'unit I andsecured by means of a plurality of nuts I6 and bolts I'I or othersuitable support means are guide rails I8 and I9. To the right and theleft of member I are movable units 2l) and 2I which are preferably thatof a tank circuit, each one of which is tuned to a different frequencyand contains tuning inductance elements 22 and 23 mounted on suitableinsulators 24 at a suitable height to engage the xed contacts 8 to II,inclusive. The base portion of members 20 and 2l contain a plurality oflow voltage switches 25, 26, 2l and 28. The movable units are providedwith a plurality of guide rollers 30, also worm nuts 3| and 32, theunits being spaced apart from each other by worm shaft 33 which isrotated by actuating mechanism 34, such as hydraulic, motor-driven orsimilar devices.

By this arrangement, one or more tubes are provided with input andoutput connections of a type which enable quick but positive connectionsto associated circuits which are also equipped with quick but positiveconnections to the tube cr tubes. By means of the rails or guides IB orby means of manually remotely controlled or automatic actuating devices,input or output circuits tuned to different frequencies may be quicklychanged at the tube or tubes. The input and/or output circuits may bemechanically or electrically interlocked so that only the desiredcircuits may be connected to the tube or tubes at any time. The sameconnecting and disconnecting system may be used to switch power supplyvoltages simultaneously. This system may be arranged so that the unusedinput and/ or output circuits may be changed to prepare for a pendingchange to another frequency, while the used circuits are in operation.By automatic means for removing dangerous voltages from unused circuitsand by providing a barrier to protect the operators, the methodsdescribed may be used to switch complete pre-tuned circuits, or circuitelements forming a part of a complete circuit or parts of completecircuits. The tubes may be equipped with a multiplicity of contactelements other than those of 8 to Il, inclusive, also, tank circuits maybe connected to it from opposite sides or from more than two directions.The circuits so connected may be coupled to their drivers or loads inthe system described, by electro-magnetic, electrostatic or capacitycoupling by proper arrangement of circuit elements. The complete inputand/or output circuits may be mechanically moved into or out of contact,or they may be fixed and the connections completed or broken byconnections so interlocked with each other that more than the desiredelements could not be connected at one time.

Referring now to Fig. 3, there is shown a threesided arrangement forswitching into and out of circuit one of three tank circuits, that is,each tank circuit being tuned to its separate or different frequency.Although this figure shows only a diagrammatic arrangement, it is to beunderstood that in each case the tank assembly moves toward the tubeassembly in a cradle, bed or track, and actuated by shafts 33 and motors34, so that the connections line up perfectly with each other. The tankcircuits should be arranged so that while either unit 40 or 4i is inoperation an additional unit 42 may be mounted in a position for thenext switching operation.

Fig. 4 of the drawing shows an arrangement similar to that of Figs. l to3, inclusive, except that there is shown a method of switching four tankcircuits 43, 44, 45 and 4G, and as mentioned above, tank circuits 43 and44 could be arranged so that while either one or two of the units are inoperation, tuning units 45 and 46 could be mounted in a position for thenext switching operation. The tank circuits 43, 44, 45 and 45 areactuated by shafts 33 and motors 34, as mentioned above in connectionwith Figs. l and 2. The operating personnel would be protected by metalscreens or shielding 41 and 48 (shown by the dotted lines) and althoughFigs. 3 and 4 show the use of three and four tank circuits, it is to beunderstood that the number of tank circuits Which may be connected tothe tube assembly has no limit beyond. a practical and economicalconsideration. Therefore, the invention should not be limited to theprecise arrangements shown.

What is claimed is:

1. A radio frequency changing system comprising a transmitter dividedinto a fixed tube assembly portion and a plurality of movable tuningassemblies arranged to surround said xed tube assembly portion, each oneof said tuning assemblies having separate shielded containers, each oneof said movable tuning assemblies being tuned to a differentpredetermined frequency, means for spacing said tuning assemblies apredetermined distance apart and for moving at least one of said tuningassemblies and establishing electrical connection between it and saidfixed tube assembly portion, and means adapted to cause another tuningassembly to be simultaneously moved and disconnected from said fixedtube assembly when said first mentioned electrical connection isestablished.

2. A radio frequency changing system comprising a transmitter dividedinto a tube assembly portion and a plurality of tuning assembliesarranged to surround said tube assembly portion` each one of said tuningassemblies having separate shielded containers, each one of said tuningassemblies being tuned to a diierent predetermined frequency, means forestablishing electrical connection between said tube assembly portionand at least one of said tuning assemblies. said means including amotor, a rotatable shaft coupled to said motor, said shaft being`arranged to space said tuning assemblies a predetermined distance apartand to simultaneously move and disconnect a tuning assembly from saidtube assembly portion when said first mentioned electrical connection isestablished therewith.

3. A radio frequency changing system comprising a transmitter dividedinto a tube assembly portion and a plurality of tuning assembliesarranged to surround said tube assembly portion, each one of said tuningassemblies having separate shielded containers, each one of said tuningassemblies being tuned to a different predetermined frequency, means forestablishing electrical connection between said tube assembly portionand at least one of said tuning assemblies. said means including atrack, a plurality of rollers arranged to run on said track, a rotatableshaft linked to said tuning assemblies and spacing them apart apredetermined distance, an actuating means coupled to said shaft tocause at least one of said tuning units to be simultaneously moved anddisconnected from said tube assembly portion when said first mentionedelectrical connection is established therewith.

4. A radio frequency changing system comprising a transmitter dividedinto a tube assembly portion and a plurality of tuning assembliesarranged to surround said tube assembly portion, each one of said tuningassemblies having separate shielded containers, each one of said tuningassemblies being tuned to a different predetermined frequency, aplurality of contacts supported by insulators secured to said tuningassemblies, means for establishing electrical connection between thecontacts of said tube assembly portion and at least one of said tuningassemblies, said means including a track, a rotatable shaft linked tosaid tuning assemblies and spacing them apart a predetermined distance,`and actuating means coupled to said shaft to cause at least one of saidtuning units to be simultaneously disconnected from said tube assemblyportion when said first mentioned electric connection is established bya plurality of ccntacts supported by insulators.

5. A radio frequency changing system comprising a transmitter dividedinto `a tube assembly portion and a plurality of tuning assemblies, saidtube 'assembly having an electron discharge device with at least ananode, said tube being insulatedly supported and provided with fixedhigh voltage contacting portions connected 'to said anode,saidfplurality of tuning assemblies located each side of said tubeassembly portion and linked together a predetermined distance apart, aninductance unit mounted upon a plurality of msulators located on eachtuning unit, the inductance of each tuning unit being 'tuned to adifferent predetermined frequency, and actuating means for makingconnection between the anode of the tube assembly portion and theinductance of the tuning assembly means adapted to cause the inductanceof one tuning assembly to Abe simultaneously disconnected from said tubeassembly portion when said first mentioned electrical connection isestablished with another one of said tuning assemblies.

6. A radio frequency changing system comprising a transmitter dividedinto a plurality of units including a Water-cooled tube assembly, afixed portion forming an input circuit for said transmitter, a pluralityof output circuits surrounding said tube assembly each one of saidoutput circuits being spaced apart a predetermined dis tance from saidtube assembly and tuned to a different predetermined frequency, aprotective metal screen interposed between said tube assembly and eachone of said output circuits, means for moving and establishingelectrical connection between said input and at least one of the outputcircuits and adapted to cause movement of said one output circuit whichsimultaneously moves and disconnects another output circuit from saidinput circuit, and a plurality of interlocking electrical connectionsfor controlling auxiliary apparatus in said input circuit.

7. A radio frequency changing system comprising a transmitter dividedinto a plurality of units including a tube assembly portion, said tubeassembly with an electron discharge device having at least an anode,said tube being insulatedly supported and provided with fixed highvoltage contacting portions connected to said anode, a plurality ofother contacts located below said high voltage contacting portions, aplurality of tuning assemblies located each side of said tube assemblyportion and spaced apart from one another a predetermined distance, aninductance unit mounted upon a plurality of insulators located on eachtuning unit, the inductance of each tuning unit being tuned to adifferent predetermined frequency, and actuating means for makingconnection between the anode of the tube assembly portion and theinductance of the tuning assembly, means adapted to cause the inductanceof one tuning assembly to be simultaneously disconnected from said tubeassembly portion when said first mentioned electrical connection isestablished with another one of said tuning assemblies.

8. In a radio frequency changing system, a fixed transmitter portionincluding a plurality of electron discharge tubes, said transmitterportion centrally mounted on a plurality of rails, a plurality of tuningmembers arranged each side of said fixed transmitter portion and to moveon said rails, an actuating member linking said tuning members togetherat a predetermined distance apart on said rails, means adapted to causemovement of said actuating member to connect one of said tuning membersto said fixed transmitter portion and to simultaneously disconnectanother tuning member.

9. In a radio frequency changing system, a fixed transmitter portioncentrally mounted on a -plurality of rails, a plurality of `tuningmembers arranged each side of said fixed transmitter portion and to moveon said rails, fixed contacts on said transmitter portion, fixedcontacts on 'said tuning members and arranged to contact the contacts onsaid transmitter portion, an actuating member coupling said tuningmembers together at a predetermined distance apart on said rails, saidactuating member adapted to cause movement of one of said tuning membersto have its contacts connect said contacts of the fixed transmitterportion and simultaneously disconnect the contacts of another tuningmember.

l0. In a radio frequency changing system, a transmitter divided into aplurality of units 1ncluding a tube assembly portion and a plurality oftuning assemblies, said tube assembly portion being centrally mountedupon a fixed platform, each one of said tuning assemblies being mountedupon a movable platform and located each side of said transmitter tubeassembly portion, a group of electrical contacts mounted on said fixedplatform, a group of electrical contacts mounted on said movableplatformsvand arranged to make contact with said first mentioned groupof electrical contacts, means for spacing said tuning assemblies apredetermined distance apart and for moving said movable platforms withrespect to said fixed platform, said actuating member adapted to causethe group of contacts on at least one of said movable platforms toconnect with the contacts on said fixed platform and disconnect a -groupof contacts on another movable platform from said fixed platform.

11. In a radio frequency changing system, a fixed transmitter portioncentrally mounted on a plurality of rails, a plurality of tuning membershaving inductive elements supported each side of said fixed transmitterby a plurality of insulating members, said tuning members arranged tomove on said rails, an actuating member linking said tuning memberstogether a predetermined distance apart on said rails, said actuatingmember adapted to cause movement of said tuning members and to connectone of them with said fixed transmitter portion and simultaneouslydisconnect another tuning member, and a shielding member interposedbetween said fixed transmitter portion and said tuning members.

12. A radio frequency changing system comprising a transmitter dividedinto a water-cooled tube assembly and a plurality of inductive tankcircuits, said tube assembly centrally mounted on a plurality of rails,said tank circuits arranged to move on said rails, an actuating memberfor moving and linking said tank circuits and said Water cooled tubeassembly together at a predetermined distance apart on said rails, saidactuating member adapted to move one tank circuit to the contacts onsaid tube assembly and simultaneously disconnect contacts of anothertank circuit.

13. A radio frequency changing system comprising a transmitter dividedinto a plurality of units including a water-cooled tube assembly, afixed portion forming an input circuit for said transmitter, a pluralityof output circuits adjacent said tube assembly, each one of said outputcircuits being tuned to a different predetermined frequency, means forlinking said output circuits at a predetermined distance apart and forestablishing electrical connection between said input and at least oneof the output circuits, means adapted to cause movement of said oneoutput circuit and to simultaneouslyv move it to disconnect anotheroutput circuit from said tubecircuit.

14. A radio frequency changingsystem comprising a transmitter dividedinto a plurality of units including a Huid-cooled tube assembly, a fixedportion forming an input circuit for said transmitter, a plurality ofoutput circuits surrounding said tube assembly, each one of said outputcircuits being tuned to a different predetermined frequency, means forlinking said output circuits a-predetermined distance apart and forestablishing electrical connection between said inputand at least one ofthe output circuitsy means adapted to cause movement of said one outputcircuit and to simultaneously move it to disconnect another outputcircuit from said input circuit, and a plurality of interlockingelectrical connections for controlling auxiliary apparatus in said inputcircuit.

RAYMOND F. GUY.

